<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title></title>
    <script src="js/jquery.min.js"></script>
    <link type="text/css" href="./css/style.css" rel="stylesheet" />
    <style>
      html,
      body {
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
        overflow: hidden;
      }
      .container {
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
        background-color: #000000;
      }
    </style>
  </head>
  <body>
    <audio autoplay="autopaly">
      <source src="renxi.mp3" type="audio/mp3" />
    </audio>
    <div id="jsi-cherry-container" class="container">
      <div class="box">
        <ul class="minbox">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <ol class="maxbox">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ol>
      </div>
    </div>

    <script>
      var RENDERER = {
        INIT_CHERRY_BLOSSOM_COUNT: 30,
        MAX_ADDING_INTERVAL: 10,

        init: function() {
          this.setParameters();
          this.reconstructMethods();
          this.createCherries();
          this.render();
          if (
            navigator.userAgent.match(
              /(phone|pod|iPhone|iPod|ios|Android|Mobile|BlackBerry|IEMobile|MQQBrowser|JUC|Fennec|wOSBrowser|BrowserNG|WebOS|Symbian|Windows Phone)/i
            )
          ) {
            var box = document.querySelectorAll('.box')[0];
            console.log(box, '移动端');
            box.style.marginTop = '65%';
          }
        },
        setParameters: function() {
          this.$container = $('#jsi-cherry-container');
          this.width = this.$container.width();
          this.height = this.$container.height();
          this.context = $('<canvas />')
            .attr({ width: this.width, height: this.height })
            .appendTo(this.$container)
            .get(0)
            .getContext('2d');
          this.cherries = [];
          this.maxAddingInterval = Math.round(
            (this.MAX_ADDING_INTERVAL * 1000) / this.width
          );
          this.addingInterval = this.maxAddingInterval;
        },
        reconstructMethods: function() {
          this.render = this.render.bind(this);
        },
        createCherries: function() {
          for (
            var i = 0,
              length = Math.round(
                (this.INIT_CHERRY_BLOSSOM_COUNT * this.width) / 1000
              );
            i < length;
            i++
          ) {
            this.cherries.push(new CHERRY_BLOSSOM(this, true));
          }
        },
        render: function() {
          requestAnimationFrame(this.render);
          this.context.clearRect(0, 0, this.width, this.height);

          this.cherries.sort(function(cherry1, cherry2) {
            return cherry1.z - cherry2.z;
          });
          for (var i = this.cherries.length - 1; i >= 0; i--) {
            if (!this.cherries[i].render(this.context)) {
              this.cherries.splice(i, 1);
            }
          }
          if (--this.addingInterval == 0) {
            this.addingInterval = this.maxAddingInterval;
            this.cherries.push(new CHERRY_BLOSSOM(this, false));
          }
        }
      };
      var CHERRY_BLOSSOM = function(renderer, isRandom) {
        this.renderer = renderer;
        this.init(isRandom);
      };
      CHERRY_BLOSSOM.prototype = {
        FOCUS_POSITION: 300,
        FAR_LIMIT: 600,
        MAX_RIPPLE_COUNT: 100,
        RIPPLE_RADIUS: 100,
        SURFACE_RATE: 0.5,
        SINK_OFFSET: 20,

        init: function(isRandom) {
          this.x = this.getRandomValue(
            -this.renderer.width,
            this.renderer.width
          );
          this.y = isRandom
            ? this.getRandomValue(0, this.renderer.height)
            : this.renderer.height * 1.5;
          this.z = this.getRandomValue(0, this.FAR_LIMIT);
          this.vx = this.getRandomValue(-2, 2);
          this.vy = -2;
          this.theta = this.getRandomValue(0, Math.PI * 2);
          this.phi = this.getRandomValue(0, Math.PI * 2);
          this.psi = 0;
          this.dpsi = this.getRandomValue(Math.PI / 600, Math.PI / 300);
          this.opacity = 0;
          this.endTheta = false;
          this.endPhi = false;
          this.rippleCount = 0;

          var axis = this.getAxis(),
            theta =
              this.theta +
              (Math.ceil(
                -(this.y + this.renderer.height * this.SURFACE_RATE) / this.vy
              ) *
                Math.PI) /
                500;
          theta %= Math.PI * 2;

          this.offsetY =
            40 * (theta <= Math.PI / 2 || theta >= (Math.PI * 3) / 2 ? -1 : 1);
          this.thresholdY =
            this.renderer.height / 2 +
            this.renderer.height * this.SURFACE_RATE * axis.rate;
          this.entityColor = this.renderer.context.createRadialGradient(
            0,
            40,
            0,
            0,
            40,
            80
          );
          this.entityColor.addColorStop(
            0,
            'hsl(330, 70%, ' + 50 * (0.3 + axis.rate) + '%)'
          );
          this.entityColor.addColorStop(
            0.05,
            'hsl(330, 40%,' + 55 * (0.3 + axis.rate) + '%)'
          );
          this.entityColor.addColorStop(
            1,
            'hsl(330, 20%, ' + 70 * (0.3 + axis.rate) + '%)'
          );
          this.shadowColor = this.renderer.context.createRadialGradient(
            0,
            40,
            0,
            0,
            40,
            80
          );
          this.shadowColor.addColorStop(
            0,
            'hsl(330, 40%, ' + 30 * (0.3 + axis.rate) + '%)'
          );
          this.shadowColor.addColorStop(
            0.05,
            'hsl(330, 40%,' + 30 * (0.3 + axis.rate) + '%)'
          );
          this.shadowColor.addColorStop(
            1,
            'hsl(330, 20%, ' + 40 * (0.3 + axis.rate) + '%)'
          );
        },
        getRandomValue: function(min, max) {
          return min + (max - min) * Math.random();
        },
        getAxis: function() {
          var rate = this.FOCUS_POSITION / (this.z + this.FOCUS_POSITION),
            x = this.renderer.width / 2 + this.x * rate,
            y = this.renderer.height / 2 - this.y * rate;
          return { rate: rate, x: x, y: y };
        },
        renderCherry: function(context, axis) {
          context.beginPath();
          context.moveTo(0, 40);
          context.bezierCurveTo(-60, 20, -10, -60, 0, -20);
          context.bezierCurveTo(10, -60, 60, 20, 0, 40);
          context.fill();

          for (var i = -4; i < 4; i++) {
            context.beginPath();
            context.moveTo(0, 40);
            context.quadraticCurveTo(i * 12, 10, i * 4, -24 + Math.abs(i) * 2);
            context.stroke();
          }
        },
        render: function(context) {
          var axis = this.getAxis();

          if (
            axis.y == this.thresholdY &&
            this.rippleCount < this.MAX_RIPPLE_COUNT
          ) {
            context.save();
            context.lineWidth = 2;
            context.strokeStyle =
              'hsla(0, 0%, 100%, ' +
              (this.MAX_RIPPLE_COUNT - this.rippleCount) /
                this.MAX_RIPPLE_COUNT +
              ')';
            context.translate(
              axis.x +
                this.offsetY * axis.rate * (this.theta <= Math.PI ? -1 : 1),
              axis.y
            );
            context.scale(1, 0.3);
            context.beginPath();
            context.arc(
              0,
              0,
              (this.rippleCount / this.MAX_RIPPLE_COUNT) *
                this.RIPPLE_RADIUS *
                axis.rate,
              0,
              Math.PI * 2,
              false
            );
            context.stroke();
            context.restore();
            this.rippleCount++;
          }
          if (axis.y < this.thresholdY || !this.endTheta || !this.endPhi) {
            if (this.y <= 0) {
              this.opacity = Math.min(this.opacity + 0.01, 1);
            }
            context.save();
            context.globalAlpha = this.opacity;
            context.fillStyle = this.shadowColor;
            context.strokeStyle =
              'hsl(330, 30%,' + 40 * (0.3 + axis.rate) + '%)';
            context.translate(
              axis.x,
              Math.max(axis.y, this.thresholdY + this.thresholdY - axis.y)
            );
            context.rotate(Math.PI - this.theta);
            context.scale(axis.rate * -Math.sin(this.phi), axis.rate);
            context.translate(0, this.offsetY);
            this.renderCherry(context, axis);
            context.restore();
          }
          context.save();
          context.fillStyle = this.entityColor;
          context.strokeStyle = 'hsl(330, 40%,' + 70 * (0.3 + axis.rate) + '%)';
          context.translate(
            axis.x,
            axis.y + Math.abs(this.SINK_OFFSET * Math.sin(this.psi) * axis.rate)
          );
          context.rotate(this.theta);
          context.scale(axis.rate * Math.sin(this.phi), axis.rate);
          context.translate(0, this.offsetY);
          this.renderCherry(context, axis);
          context.restore();

          if (this.y <= -this.renderer.height / 4) {
            if (!this.endTheta) {
              for (
                var theta = Math.PI / 2, end = (Math.PI * 3) / 2;
                theta <= end;
                theta += Math.PI
              ) {
                if (this.theta < theta && this.theta + Math.PI / 200 > theta) {
                  this.theta = theta;
                  this.endTheta = true;
                  break;
                }
              }
            }
            if (!this.endPhi) {
              for (
                var phi = Math.PI / 8, end = (Math.PI * 7) / 8;
                phi <= end;
                phi += (Math.PI * 3) / 4
              ) {
                if (this.phi < phi && this.phi + Math.PI / 200 > phi) {
                  this.phi = Math.PI / 8;
                  this.endPhi = true;
                  break;
                }
              }
            }
          }
          if (!this.endTheta) {
            if (axis.y == this.thresholdY) {
              this.theta +=
                (Math.PI / 200) *
                (this.theta < Math.PI / 2 ||
                (this.theta >= Math.PI && this.theta < (Math.PI * 3) / 2)
                  ? 1
                  : -1);
            } else {
              this.theta += Math.PI / 500;
            }
            this.theta %= Math.PI * 2;
          }
          if (this.endPhi) {
            if (this.rippleCount == this.MAX_RIPPLE_COUNT) {
              this.psi += this.dpsi;
              this.psi %= Math.PI * 2;
            }
          } else {
            this.phi += Math.PI / (axis.y == this.thresholdY ? 200 : 500);
            this.phi %= Math.PI;
          }
          if (this.y <= -this.renderer.height * this.SURFACE_RATE) {
            this.x += 2;
            this.y = -this.renderer.height * this.SURFACE_RATE;
          } else {
            this.x += this.vx;
            this.y += this.vy;
          }
          return (
            this.z > -this.FOCUS_POSITION &&
            this.z < this.FAR_LIMIT &&
            this.x < this.renderer.width * 1.5
          );
        }
      };
      $(function() {
        RENDERER.init();
      });
    </script>
  </body>
</html>
